2026 ICD-10-CM Diagnosis Code Q79.1Other congenital malformations of diaphragm

ICD-10-CM Codes›Q00-Q99›Q65-Q79›Q79

ICD-10-CM Q79.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q79.1 is a billable ICD-10-CM diagnosis code for other congenital malformations of diaphragm. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 205 through 206. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Musculoskeletal congenital conditions.

Code Identity

ICD-10-CM Code
Q79.1
Billable Status
Yes — Valid for Submission
Code Describes
Other congenital malformations of diaphragm
Short Description
Other congenital malformations of diaphragm
Same as the full description in the CMS dataset.
Parent Code
Q79
Congenital malformations of musculoskeletal system, not elsewhere classified

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ65-Q79Congenital malformations and deformations of the musculoskeletal system
CategoryQ79Congenital malformations of musculoskeletal system, not elsewhere classified
This CodeQ79.1Other congenital malformations of diaphragm

Present on Admission (POA)Billing

Q79.1 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Agenesis of diaphragm
  • Aplasia of diaphragm
  • Congenital absence of diaphragm
  • Congenital absence of left hemidiaphragm
  • Congenital absence of right hemidiaphragm
  • Congenital absent hemidiaphragm - bilateral
  • Congenital anomaly of diaphragm
  • Congenital anomaly of pericardium
  • Congenital cleft hand
  • Congenital diaphragmatic hernia
  • Congenital eventration of diaphragm
  • Congenital eventration of left crus of diaphragm
  • Congenital eventration of right crus of diaphragm
  • Congenital hypoplasia of diaphragm
  • Congenital posterolateral diaphragmatic hernia
  • Diaphragmatic defect, limb deficiency, skull defect syndrome
  • Diaphragmatic eventration
  • Elevated diaphragm
  • Pericardial and diaphragmatic defect syndrome
  • Pericardial anomaly
  • Split hand, obstructive uropathy, spina bifida, diaphragmatic defect syndrome

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Absence of diaphragm
  • Congenital malformation of diaphragm NOS
  • Eventration of diaphragm

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Abnormal, abnormality, abnormalities
      • apertures, congenital, diaphragm
    • Absence(of) (organ or part) (complete or partial)
      • diaphragm (with hernia), congenital
    • Agenesis
      • diaphragm (with hernia)
    • Anomaly, anomalous(congenital) (unspecified type)
      • diaphragm (apertures) NEC
    • Defect, defective
      • diaphragm
        • congenital
    • Deformity
      • diaphragm (congenital)
    • Elevated, elevation
      • diaphragm, congenital
    • Enlargement, enlarged
      • apertures of diaphragm (congenital)
    • Eventration
      • diaphragm (congenital)
    • High
      • diaphragm (congenital)
    • Hypertrophy, hypertrophic
      • esophageal hiatus (congenital)
    • Hypertrophy, hypertrophic
      • hiatus (esophageal)
    • Malformation(congenital)
      • diaphragm

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MAL008
Musculoskeletal congenital conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Diaphragmatic Eventration

    a congenital abnormality characterized by the elevation of the diaphragm dome. it is the result of a thinned diaphragmatic muscle and injured phrenic nerve, allowing the intra-abdominal viscera to push the diaphragm upward against the lung.

  • Congenital Diaphragmatic Hernia

    diaphragmatic hernia that is present at birth.

  • Pericardial Anomaly

    any abnormality involving the pericardium.

Patient EducationClinical

Birth Defects

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect.

The full article covers:

  • What are birth defects?
  • What causes birth defects?
  • Who is at risk of having a baby with birth defects?
  • How are birth defects diagnosed?
  • What are the treatments for birth defects?
  • Can birth defects be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Q79.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
756.6 Anomalies of diaphragm
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Q79.1Overview

Is Q79.1 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other congenital malformations of diaphragm on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Q79.1 group to?

When other congenital malformations of diaphragm is the principal diagnosis on an inpatient stay, it groups to MS-DRG 205, 206, with relative weights from 0.9411 to 1.8310 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q79.1 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for other congenital malformations of diaphragm on inpatient claims.

What is the ICD-9 equivalent of Q79.1?

Under the General Equivalence Mappings, other congenital malformations of diaphragm converts to ICD-9-CM 756.6 (anomalies of diaphragm). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.